Question

我目前正在编写一个小网络的东西，并希望cicle扔掉我的所有玩家，所以我使用了ArrayLists和Lists但是有很多Exception，所以深入到问题我用迭代器替换它们但是我得到并发修改所有“it.next（）”中的异常：/。所以如果请你能帮助我理解这个问题：）。

    @Override
public void run()
{
    StringBuilder l = new StringBuilder();
    Iterator<UUID> pc;
    Iterator<Packet> pa;
    while (Jelly.isSTATUS()) {
        pc = Jelly.getOnlinePlayers().keySet().iterator();
        while (pc.hasNext())
            try {
                System.out.println("ENTERED!");
                Player p = Jelly.getOnlinePlayers().get(pc.next());
                System.out.println(p.getIGN());
                if (Packetsts.containsKey(p) && !Packetsts.get(p).isEmpty())
                    try {
                        pa = Packetsts.get(p).iterator();
                        while(pa.hasNext()) {
                            Packet i = pa.next();
                            for ( String j : i.getData())
                                l.append(j + ",");
                            l.append("es");

                            System.out.println("Data: " + l.toString());
                            byte[] toSendBytes = l.toString().getBytes();
                            int toSendLen = toSendBytes.length;
                            byte[] toSendLenBytes = new byte[4];
                            toSendLenBytes[0] = (byte)(toSendLen & 0xff);
                            toSendLenBytes[1] = (byte)(toSendLen >> 8 & 0xff);
                            toSendLenBytes[2] = (byte)(toSendLen >> 16 & 0xff);
                            toSendLenBytes[3] = (byte)(toSendLen >> 24 & 0xff);
                            PrintStreams.get(p).write(toSendLenBytes);
                            PrintStreams.get(p).write(toSendBytes);

                            Packetsts.get(p).remove(i);
                            l.setLength(0);
                        }
                    } catch ( Exception ex) { }
            } catch (ConcurrentModificationException ex){ ex.printStackTrace(); }
    }
    System.out.println("END!");
}

谢谢：）

更新：

    @Override
public void run()
{
    StringBuilder l = new StringBuilder();
    Iterator<UUID> pc = Jelly.getOnlinePlayers().keySet().iterator();
    Iterator<Packet> pa;
    while (Jelly.isSTATUS())
        if (!Jelly.getOnlinePlayers().keySet().isEmpty()) {
            pc = Jelly.getOnlinePlayers().keySet().iterator();
            while (pc.hasNext()) {
                UUID u = pc.next();
                Player p = Jelly.getOnlinePlayers().get(u);
                if (Packetsts.containsKey(p) && !Packetsts.get(p).isEmpty())
                    try {
                        pa = Packetsts.get(p).iterator();
                        while(pa.hasNext()) {
                            Packet i = pa.next();
                            for ( String j : i.getData())
                                l.append(j + ",");
                            l.append("es");

                            System.out.println("Data: " + l.toString());
                            byte[] toSendBytes = l.toString().getBytes();
                            int toSendLen = toSendBytes.length;
                            byte[] toSendLenBytes = new byte[4];
                            toSendLenBytes[0] = (byte)(toSendLen & 0xff);
                            toSendLenBytes[1] = (byte)(toSendLen >> 8 & 0xff);
                            toSendLenBytes[2] = (byte)(toSendLen >> 16 & 0xff);
                            toSendLenBytes[3] = (byte)(toSendLen >> 24 & 0xff);
                            PrintStreams.get(p).write(toSendLenBytes);
                            PrintStreams.get(p).write(toSendBytes);

                            l = new StringBuilder();
                        }
                        Packetsts.get(p).clear();
                    } catch ( Exception ex) { ex.printStackTrace(); }
            }
        }
    System.out.println("END!");
}

行“UUID u = pc.next（）;”拜托，我真的很讨厌并发修改异常：/

Answer 1

这是不允许的

Packetsts.get(p).remove(i);

因为您正在迭代您尝试修改的ArrayList。如何在循环开始时复制它？删除元素后，您的最终目标是什么？

iterator.next（）中的ConcurrentModificationException我找不到另一个解决方案

1 个答案: